<!DOCTYPE html>
<html>
<head>
<meta charset=UTF-8 />
<title>无标题文档</title>
<style>
p.p_num {
    width: 78px;
    height: 24px;
    border-top: solid 1px #d0d0d0;
    position: relative;
    border-bottom: solid 1px #d0d0d0;
    margin-top: -3px;
}
 
span.sy_minus,span.sy_plus {
    width: 15px;
    height: 24px;
    line-height: 24px;
    text-align: center;
    display: block;
    position: absolute;
    top: 0px;
    font-size: 14px;
    border: solid 1px #d0d0d0;
    background: #ebebeb;
    cursor: pointer;
    border-top: none;
    border-bottom: none;
}
 
span.sy_minus {
    left: 0px;
}
 
span.sy_plus {
    right: 0px;
}
 
input.sy_num {
    width: 44px;
    height: 18px;
    line-height: 24px;
    text-align: center;
    position: absolute;
    top: 0px;
    left: 17px;
}
 
span.sy_num {
    padding: 5px 8px;
    border: solid 1px #d0d0d0;
    border-left: none;
    border-right: none;
    cursor: pointer;
}
</style>
<script type="text/javascript" src="js/jquery-1.8.0.min.js"></script>
<script type="text/javascript">
    $(document).ready (function ()
    {
        var pl = $("p:last");
        var reg = /(.*[\:\：]\s*)([\+\d\.]+)(\s*元)/g;
        $ (".sy_minus").click (function ()
        {
            var me = $ (this), txt = me.next (":text"), pc = me.closest("p");
            var val = parseFloat (txt.val ());
            val = val < 1 ? 1 : val;
            txt.val (val - 1);
            var price = parseFloat (pc.prev("p").text().replace(reg,'$2')) * txt.val ();
            pc.next("p").text (pc.next("p").text().replace(reg, "$1" + price + "$3"));
            var sum = 0;
            $(".p_num").next("p").each(function (i, dom)
            {
                sum += parseFloat ($(this).text().replace(reg, "$2"));
            });
            pl.text(pl.text().replace(reg, "$1" + sum + "$3"));
        });
         
        $(".sy_plus").click (function ()
        {
            var me = $ (this), txt = me.prev (":text"), pc = me.closest("p");
            var val = parseFloat (txt.val ());
            txt.val (val + 1);
            var price = parseFloat (pc.prev("p").text().replace(reg,'$2')) * txt.val ();
            pc.next("p").text (pc.next("p").text().replace(reg, "$1" + price + "$3"));
            var sum = 0;
            $(".p_num").next("p").each(function (i, dom)
            {
                sum += parseFloat ($(this).text().replace(reg, "$2"));
            });
            pl.text(pl.text().replace(reg, "$1" + sum + "$3"));
        });
    })[0].onselectstart = new Function ("return false");
</script>
</head>
<body>
    <div class="">
        <p class="">单价：36元</p>
        <p class="p_num">
            <span class="sy_minus" id="sy_minus_gid1">-</span> 
            <input class="sy_num" id="sy_num_gid1" readonly="readonly" type="text" name="number1" value="1" /> 
            <span class="sy_plus" id="sy_plus_gid1">+</span>
        </p>
        <p class="">需支付：36元</p>
    </div>
    <div class="">
        <p class="">单价：58元</p>
        <p class="p_num">
            <span class="sy_minus" id="sy_minus_gid2">-</span> 
            <input class="sy_num" id="sy_num_gid2" readonly="readonly" type="text" name="number1" value="1" /> 
            <span class="sy_plus" id="sy_plus_gid2">+</span>
        </p>
        <p class="">需支付：58元</p>
    </div>
    <p class="">总共需要支付：94元</p>
</body>
</html>